Production of vinyl acetate in a catalytic reactor equipped with filter and distribution bed

Abstract

A process for the production of vinyl acetate (VA) by reaction in the vapor phase of ethylene, oxygen and acetic acid as reactants, comprising passing at a temperature sufficient to initiate the reaction, a feed gas comprising said reactants and continuously or intermittently containing liquid acetic acid and/or non-volatile components, through a filter and distribution bed of inert material having throughout its volume substantial intercommunicating open spaces among the solid portions, and thence through a plurality of tubes each containing a bed of catalyst for the reaction, and withdrawing a product gas comprising VA. The filter and distribution bed acts to filter out the liquid acetic acid and/or non-volatile components and distribute more evenly the feed gas into the tubes.

What is claimed is: 
     
       1. A process for the production of vinyl acetate (VA) by reaction in the vapor phase of ethylene, oxygen and acetic acid as reactants, comprising passing at a temperature sufficient to initiate the reaction, a feed gas comprising said reactants, and continuously or intermittently containing liquid acetic acid and/or non-volatile components, through a filter and distribution bed of inert material having throughout its volume substantial intercommunicating open spaces among the solid portions, and into a plurality of tubes each containing a bed of a catalyst for the reaction, and withdrawing a product gas comprising VA, said filter and distribution bed acting to filter out at least some of said liquid acetic acid and/or non-volatile components and distribute more evenly said feed gas into said tubes. 
     
     
       2. The process of claim 1 wherein said reaction is carried out in a reactor having the configuration of a tube and shell heat exchanger containing open-ended tubes secured between two rigid tubesheets wherein each tube contains a bed of catalyst for the reaction in its midportion between the tubesheets, and said filter and distribution bed covers the entire upstream face of the inlet tubesheet. 
     
     
       3. The process of claim 2 where said reactor is in a vertical position and said feed and product gas flow from top to bottom. 
     
     
       4. The process of claim 1 where said inert material is composed of discrete particles. 
     
     
       5. The process of claim 1 where said catalyst comprises a porous support containing catalytically effective amounts of metallic palladium and gold. 
     
     
       6. The process of claim 5 wherein said filter and distribution bed is composed of the same inert discrete particles as the carrier of said catalyst. 
     
     
       7. A distribution filter bed for use in production of VA, comprising a mass of discrete particles at a size which is effective to distribute more evenly a feed gas into reaction tubes containing a catalyst bed, said filter bed to filter out a substantial proportion of non-volatiles in the feed gas without causing an unduly large pressure drop across the bed. 
     
     
       8. The filter bed of claim 7 wherein the discrete particles are selected from the group consisting of silica, alumina, silica-alumina, titania, zirconia, silicates, aluminosilicates, titanates, spinel, silicon carbide, and carbon.